Impacts of Process Parameters on Shape Memory Properties of Stereolithography Manufactured Parts: An Experimental Analysis

2021 ◽  
Author(s):  
Jing Zhao ◽  
Muyue Han ◽  
Lin Li
Keyword(s):  
Shape Memory ◽  
Process Parameters ◽  
Smart Materials ◽  
Manufacturing Systems ◽  
Memory Performance ◽  
Hold Time ◽  
Printing Process ◽  
Thermomechanical Process ◽  
Shape Memory Properties ◽  
Scan Speed

Abstract The emergence of smart materials coupled with additive manufacturing technology has provided competitive advantages over traditional manufacturing systems in terms of manufacturing flexibility, product functionality, and the ability to switch between multiple phases under given external stimuli. Although the fabricability of shape memory materials has been widely explored in stereolithography systems, the shape memory performance of printed smart structures has not been extensively studied. More specifically, in current literature, the printing process is mainly considered independent of material characteristics, and a lack of information is reported on how the printing parameters affect the shape fixity and free recovery performance of the printed parts. Therefore, this work is dedicated to experimentally investigating the influences of parameters from both the stereolithography printing process and thermomechanical process (i.e., shape programming and free recovery) on the shape memory properties. Five parameters, including layer thickness, scan speed, maximum programmed angle, hold time, and recovery time, are experimentally analyzed for their impacts on the shape morphing capabilities. According to the results of this study, a variation of 14.33% on the free recovery ratio can be observed when the scan speed is altered. In addition, the printing process parameters exhibit high levels of dominance in affecting the shape memory performance over parameters involved in the thermomechanical process, such as hold time and maximum programmed angle.

Deformation rate-, hold time-, and cycle-dependent shape-memory performance of Veriflex-E resin

2011 ◽  
Vol 17 (1) ◽  
pp. 39-52 ◽  
Author(s):  
Amber J. W. McClung ◽  
Gyaneshwar P. Tandon ◽  
Jeffery W. Baur
Keyword(s):  
Shape Memory ◽  
Deformation Rate ◽  
Memory Performance ◽  
Hold Time ◽  
Cycle Dependent

scholarly journals Mechanical, Thermal, and Shape Memory Properties of Three-Dimensional Printing Biomass Composites

Polymers ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1234 ◽  
Author(s):  
Hongjie Bi ◽  
Min Xu ◽  
Gaoyuan Ye ◽  
Rui Guo ◽  
Liping Cai ◽  
...  
Keyword(s):  
Shape Memory ◽  
Wood Flour ◽  
Memory Performance ◽  
Thermoplastic Polyurethane ◽  
Tensile Elongation ◽  
Three Dimensional ◽  
Mechanical Analysis ◽  
Shape Memory Properties ◽  
Shape Memory Composites ◽  
Recovery Angle

In this study, a series of heat-induced shape memory composites was prepared by the hot-melt extrusion and three-dimensional (3D) printing of thermoplastic polyurethane (TPU) using wood flour (WF) with different contents of EPDM-g-MAH. The mechanical properties, microtopography, thermal property analysis, and heat-induced shape memory properties of the composites were examined. The results showed that, when the EPDM-g-MAH content was 4%, the tensile elongation and tensile strength of the composites reached the maximum value. The scanning electron microscopy and dynamic mechanical analysis results revealed a good interface bonding between TPU and WF when the EPDM-g-MAH content was 4%. The thermogravimetric analysis indicated that the thermal stability of TPU/WF composites was enhanced by the addition of 4% EPDM-g-MAH. Heat-induced shape memory test results showed that the shape memory performance of composites with 4% EPDM-g-MAH was better than that of unmodified-composites. The composites’ shape recovery performance at a temperature of 60 °C was higher than that of the composites at ambient temperature. It was also found that, when the filling angle of the specimen was 45°, the recovery angle of the composites was larger.

The Two-Stage Curing Method for Shape-Memory Materials

2012 ◽  
Vol 476-478 ◽  
pp. 2227-2230
Author(s):  
He Sun ◽  
Yu Yan Liu ◽  
Hui Feng Tan ◽  
Chang Guo Wang
Keyword(s):  
Shape Memory ◽  
Memory Performance ◽  
Mechanical Analysis ◽  
Scanning Calorimetry ◽  
Two Stage ◽  
Memory Tests ◽  
Second Stage ◽  
Shape Memory Properties ◽  
Shape Memory Materials ◽  
Curing Method

In this paper, a various shape-memory materials had been prepared by two-stage curing method. The purpose of using this approach was to maintain the excellent shape memory properties and low glass transition temperature (Tg) of shape-memory materials after first stage curing, furthermore, improve the Tg and heat resistence effectively after second stage curing. Differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA) and fold-deploy shape memory tests were used to characterize the feasibility of two-stage curing, thermodynamics properties and shape memory performance of these polymers. DSC results showed that two different curing stages could be achieved successfully, DMA results suggested that heat resistance of materials had been improved after second curing stage, while the fold-deploy shape memory tests proved that the composites possessed excellent shape memory properties, it could be deformed into different shape and recovered its original shape fully within three minutes.

Influence of Be and Ni to Cu-Al Alloy Shape Memory Performance

2011 ◽  
Vol 197-198 ◽  
pp. 1258-1262 ◽  
Author(s):  
Hua Ping Xu ◽  
Gao Feng Song ◽  
Xie Min Mao
Keyword(s):  
Shape Memory Alloy ◽  
Single Crystal ◽  
Shape Memory ◽  
Directional Solidification ◽  
Ternary Alloy ◽  
Memory Performance ◽  
Al Alloy ◽  
Strengthening Effect ◽  
Shape Memory Properties

With Bridgeman directional solidification method the single crystal alloys of CuAl base shape memory alloy (SMA) with different components were prepared. And their shape memory performance characters were systematically investigated. The results show that the single crystal of CuAlNiBe quaternary shape memory alloy has much better shape memory properties than that of the CuAlBe and CuAlNi ternary alloy. That meant that in the CuAl base SMA alloy the mixed addition of Be and Ni changed the quenching microstructure has a strengthening effect to improve the shape memory performance of the SMA alloy.

A Study on Shape Memory Performance of Cu-Al-Ni-Be Alloy Single Crystal

2011 ◽  
Vol 287-290 ◽  
pp. 21-25
Author(s):  
Hua Ping Xu ◽  
Gao Feng Song ◽  
Xie Min Mao
Keyword(s):  
High Temperature ◽  
Temperature Gradient ◽  
Shape Memory Alloy ◽  
Single Crystal ◽  
Shape Memory ◽  
Directional Solidification ◽  
Memory Performance ◽  
Copper Base ◽  
Shape Memory Properties ◽  
Solidification Furnace

In this paper, single crystal of CuAlNiBe quaternary shape memory alloy was prepared in a high temperature gradient directional solidification furnace with a selective growing crystallizer. And its shape memory performance characters were systematically compared with other series copper base shape memory alloys. The results show that the single crystal of CuAlNiBe quaternary shape memory alloy has better shape memory properties.

Influence of Radialization Dosage on Shape Memory Effect of Polystyrene Copolymer

2008 ◽  
Vol 47-50 ◽  
pp. 690-693 ◽  
Author(s):  
Da Wei Zhang ◽  
Jin Song Leng ◽  
Yan Ju Liu
Keyword(s):  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Smart Materials ◽  
Shape Recovery ◽  
Memory Performance ◽  
Shape Memory Polymer ◽  
Shape Memory Polymers ◽  
Mechanical Analysis ◽  
Styrene Copolymer

This paper is concerned about the synthesis of shape memory styrene copolymer and the investigation of the influence of radialization dosage on its shape memory effect. As one of novel actuators in smart materials, shape memory polymers (SMPs) have been investigated intensively. Styrene copolymer with proper cross-linking degree can exhibit shape memory effect (SME). In this paper, the influence of radialization on shape memory effect of styrene copolymer was investigated through altering the dosage of radialization. The radialization dosage of styrene copolymer was determined by changed radicalization time. The glass transition temperature (Tg) of styrene copolymerwas measured by Dynamic Mechanical Analysis (DMA). The shape memory performance of styrene copolymer with different radiated dosage was also evaluated. Results indicated that the shape memory polymer (SMP) was synthesized successfully. The Tg increased from 60°C to 65°C followed by increasing the radialization dosage. Moreover, the SMP experienced good SME and the largest reversible strain of the SMP reached as high as 150%. When heating above Tg+30°C (different copolymers performed different Tg), the shape recovery speed of the copolymers increased with increasing the radialization dosage. However, the recovery speed decreased with increasing the radialization dosage at the same temperature of 95°C.

Predicting Polyurethane Shape Memory Behaviors in Stress-Controlled Situations Using a Viscoelastic Model

2013 ◽  
Vol 575-576 ◽  
pp. 101-106
Author(s):  
Zhao Jing Wang ◽  
Ling Luo ◽  
Yu Xi Jia ◽  
Jun Peng Gao ◽  
Xiao Su Yi
Keyword(s):  
Shape Memory ◽  
Heating Rate ◽  
Smart Materials ◽  
Memory Performance ◽  
Superposition Principle ◽  
Viscoelastic Model ◽  
Maxwell Model ◽  
Generalized Maxwell Model ◽  
Potential Applications ◽  
Time Temperature Superposition Principle

As an outstanding class in smart materials of particular interest, shape memory polymers (SMPs) and their composites are drawing more and more attentions due to their potential applications in fields like biomedical and spacecraft industry. In this paper, shape memory behaviors of polyurethane (PU) in stress-controlled situations are simulated on the basis of the generalized Maxwell model and the time-temperature superposition principle. The free recovery cycles under three different imposed stresses and the influence on shape memory behaviors caused by changing heating rate are discussed. As the results reveal, the generalized Maxwell model can be used to describe the PU shape memory performance, and the shape recovery temperature increases with the increase of heating rate.

scholarly journals Coupling Dynamic Covalent Bonds and Ionic Crosslinking Network to Promote Shape Memory Properties of Ethylene-vinyl Acetate Copolymers

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 983 ◽  
Author(s):  
Wenjing Wu ◽  
Sreeni Narayana Kurup ◽  
Christopher Ellingford ◽  
Jie Li ◽  
Chaoying Wan
Keyword(s):  
Tensile Strength ◽  
Shape Memory ◽  
Vinyl Acetate ◽  
Mechanical Performance ◽  
Memory Performance ◽  
Ethylene Vinyl Acetate ◽  
Crosslinking Density ◽  
Melt Processing ◽  
Covalent Bonds ◽  
Shape Memory Properties

Dynamic crosslinking networks based on Diels–Alder (DA) chemistry and ionic interactions were introduced to maleic anhydride modified ethylene-vinyl acetate copolymer (mEVA) via in situ melt processing. The dual dynamic crosslinking networks were characterized by temperature-dependent FTIR, and the effects on the shape memory properties of mEVA were evaluated with dynamic mechanical thermal analysis and cyclic tensile testing. A crosslinking density was achieved at 2.36 × 10−4 mol·cm−3 for DA-crosslinked mEVA; as a result, the stress at 100% extension was increased from 3.8 to 5.6 MPa, and tensile strength and elongation at break were kept as high as 30.3 MPa and 486%, respectively. The further introduction of 10 wt % zinc methacrylate increased the dynamic crosslinking density to 3.74 × 10−4 mol·cm−3 and the stress at 100% extension to 9.0 MPa, while providing a tensile strength of 28.4 MPa and strain at break of 308%. The combination of reversible DA covalent crosslinking and ionic network in mEVA enabled a fixing ratio of 76.4% and recovery ratio of 99.4%, exhibiting an enhanced shape memory performance, especially at higher temperatures. The enhanced shape memory and mechanical performance of the dual crosslinked mEVA showed promising reprocessing and recycling abilities of the end-of-life products in comparison to traditional peroxide initiated covalent crosslinked counterparts.

An investigation on electro-induced shape memory performances of CE/EP/CB/SCF composites applied for deployable structure

2020 ◽  
Vol 40 (3) ◽  
pp. 203-210 ◽  
Author(s):  
Tianning Ren ◽  
Guangming Zhu ◽  
Yi Liu ◽  
Xiao Hou
Keyword(s):  
Carbon Black ◽  
Shape Memory ◽  
Memory Performance ◽  
Shape Memory Polymer ◽  
Content Increase ◽  
Deployable Structure ◽  
Shape Memory Properties ◽  
Shape Memory Composites ◽  
Shape Memory Composite ◽  
Short Carbon

AbstractThe objective of this work is to investigate the thermomechanical, electrical, and shape-memory properties of bisphenol A-type cyanate ester (BACE)/polybutadiene epoxy (PBEP)/carbon black (CB) composite and assess its feasibility applied for deployable structure. Using a BACE/PBEP polymer as matrix and superconducting carbon black (CB) and short carbon fibers (SCFs) as reinforcing material, the shape memory composite was prepared by compression molding. The effects of CB and SCF content on the shape memory properties of the composites were investigated. The results demonstrate that the glass transition temperature (Tg) and the storage modulus of the composites increases as SCFs content increase. Because of the synergic effect of CB and SCFs, the shape memory composites exhibit excellent shape memory performance, and the shape recovery ratio is about 100%. With the increase in SCF content, the recovery time decreased, and the volume electrical resistivity of the composite could decrease by adding a small amount of SCFs. According to the above results, a shape memory polymer composite deployable structure was prepared.

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